What is the focal length of a convex len...

What is the focal length of a convex lens of focal length 30cm in contact with a concave lens of focal length 20cm? Is the system a converging or a diverging lens? Ignore thickness of the lenses.

Text Solution

Verified by Experts

A diverging lens of focal length 60 cm

Topper's Solved these Questions

RAY OPTICS AND OPTICAL INSTRUMENTS
NCERT GUJARATI|Exercise EXERCISES|40 Videos
NUCLEI
NCERT GUJARATI|Exercise ADDITIONAL EXERCISES|9 Videos
SEMICONDUCTOR ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS
NCERT GUJARATI|Exercise ADDITIONAL EXERCISES|8 Videos

Similar Questions

Explore conceptually related problems

A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. The power of the combination is ..........

Focal length of thin lens ......

The size of the image of an object, which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the image

The focal length of the eye lens is changed due to the action of the……….

Convex lens of focal length A and concave lens of focal length B are kept in contact, then the effective focal length of system is .......

An object O is kept infront of a converging lens of focal length 30 cm behind which there is a plane mirror at 15 cm from the lens.

The change in focal length of an eye lens is caused by the action of the …

The focal length of the lens in a photographic camera is 5cm. what is the power of the lens?

The following objects are placed one after each other in given order onto a central axis with a separation of 40 cm each. A point source of light O. a diverging lens of focal length 40 cm. a converging lens of focal length 40 cm and converging mirror of focal length 80 cm. The aperture diameter of lenses and mirror is d=20 cm . If a point source of light is placed at a perpendicular distance of x from central axis then. (You have to consider single optical event at any optical element) Mark the CORRECT statement(s):-

NCERT GUJARATI-RAY OPTICS AND OPTICAL INSTRUMENTS-EXERCISES

A beam of light converges at a point P. Now a lens is placed in the pa...
Text Solution
|
An object of size 3.0cm is placed 14cm in front of a concave lens of f...
Text Solution
|
What is the focal length of a convex lens of focal length 30cm in cont...
Text Solution
|
A compound microscope consists of an objective lens of focal length 2....
Text Solution
|
A person with a normal near point (25 cm) using a compound microscope ...
Text Solution
|
A small telescope has an objective lens of focal length 144cm and an e...
Text Solution
|
(a) A giant refracting telescope at an observatory has an objective le...
Text Solution
|
Use the mirror equation to deduce that: (a) an object placed between...
Text Solution
|
A small pin fixed on a table top is viewed from above from a distance ...
Text Solution
|
(a) Figure 9.32 shows a cross-section of a 'light pipe' made of a glas...
Text Solution
|
Answer the following questions: (a) You have learnt that plane and c...
Text Solution
|
Answer the following questions: (b) A virtual image, we always say, ...
Text Solution
|
Answer the following questions: (c) A diver under water, looks obliq...
Text Solution
|
Answer the following questions: (d) Does the apparent depth of a tan...
Text Solution
|
Answer the following questions: (e) The refractive index of diamond ...
Text Solution
|
The image of a small electric bulb fixed on the wall of a room is to b...
Text Solution
|
A screen is placed 90cm from an object. The image of the object on the...
Text Solution
|
(a) Determine the 'effective focal length' of the combination of the t...
Text Solution
|
At what angle should a ray of light be incident on the face of a prism...
Text Solution
|
A card sheet divided into squares each of size 1 mm^(2) is being viewe...
Text Solution
|